Unavoidable drainage ditches, culverts, vents, ducts, and other openings should be protected by securely fastened welded-bar grills when they have a cross-sectional area greater than:

Unavoidable drainage ditches, culverts, vents, ducts, and other openings should be protected by securely fastened welded-bar grills when they have a cross-sectional area greater than:
A . 10 square inches
B . 48 square inches
C . 64 square inches
D . 96 square inches
E . 04 square inches

View Answer

Answer: D